826 research outputs found
Is the technical performance of young soccer players influenced by hormonal status, sexual maturity, anthropometric profile, and physical performance?
The aim of this study was to examine the influence of hormonal status, anthropometric profile, sexual maturity level, and physical performance on the technical abilities of 40 young male soccer players during small-sided games (SSGs). Anthropometric profiling, saliva sampling, sexual maturity assessment (Tanner scale), and physical performance tests (Yo-Yo and vertical jumps) were conducted two weeks prior to the SSGs. Salivary testosterone was determined by the enzyme-linked immunosorbent assay method. Technical performance was determined by the frequency of actions during SSGs. Principal component analyses identified four technical actions of importance: total number of passes, effectiveness, goal attempts, and total tackles. A multivariate canonical correlation analysis was then employed to verify the prediction of a multiple dependent variables set (composed of four technical actions) from an independent set of variables, composed of testosterone concentration, stage of pubic hair and genitalia development, vertical jumps and Yo-Yo performance. A moderate-to-large relationship between the technical performance set and the independent set was observed. The canonical correlation was 0.75 with a canonical R2 of 0.45. The highest structure coefficient in the technical performance set was observed for tackles (0.77), while testosterone presented the highest structure coefficient (0.75) for the variables of the independent set. The current data suggest that the selected independent set of variables might be useful in predicting SSG performance in young soccer players. Coaches should be aware that physical development plays a key role in technical performance to avoid decision-making mistakes during the selection of young players
Temporal Changes in Technical and Physical Performances During a Small-Sided Game in Elite Youth Soccer Players
Background: There have been claims that small-sided games (SSG) may generate an appropriate environment to develop youth playersâ technical performance associated to game-related problem solving. However, the temporal change in technical performance parameters of youth players during SSG is still unknown..
Objectives: The aim of this study was to examine temporal changes in technical and physical performances during a small-sided game (SSG) in elite soccer players..
Methods: Sixty elite youth players (age 14.8 ± 0.2 yr; stature 177 ± 5 cm; body mass 66.2 ± 4.7 kg) completed a 5 v 5 SSG using two repetitions of 8 minutes interspersed by 3 minutes of passive recovery. To evaluate temporal changes in performance, the data were analysed across 4 minutes quarters. Physical performance parameters included the total distance covered (TDC), the frequency of sprints (>18 kmâąh-1), accelerations and decelerations (> 2.0 mâąs-2 and - 2.0 mâąs-2), metabolic power (Wâąkg-1), training impulse (TRIMP), TDC: TRIMP, number of impacts, and body load. Technical performance parameters included goal attempts, total number of tackles, tackles and interceptions, total number of passes, and passes effectiveness..
Results: All physical performance parameters decreased from the first to the last quarter with notable declines in TDC, metabolic power and the frequency of sprints, accelerations and decelerations (P 0.05; trivial ES for 1st v 4th quarters: 0.15 - 0.33)..
Conclusions: The data demonstrate that technical performance is maintained despite substantial declines in physical performance during a SSG in elite youth players. This finding may have implications for designing SSGâs for elite youth players to ensure physical, technical and tactical capabilities are optimized. Modifications in player number, pitch dimensions, rules, coach encouragement, for instance, should be included taking into account the main aim of a given session and then focused on overloading physical or technical elements.
Brazilian guidelines for the diagnosis of narcolepsy
Este artigo relata as conclusĂ”es da reuniĂŁo de consenso com mĂ©dicos especialistas sobre diagnĂłstico de narcolepsia baseada na revisĂŁo dos artigos sobre narcolepsia listados no Medline entre 1980 e 2010. A narcolepsia Ă© uma doença crĂŽnica de inĂcio entre a primeira e segunda dĂ©cadas de vida do indivĂduo. Os sintomas essenciais sĂŁo cataplexia e sonolĂȘncia excessiva. A cataplexia Ă© definida como episĂłdios sĂșbitos, recorrentes e reversĂveis de fraqueza da musculatura esquelĂ©tica desencadeados por situaçÔes de conteĂșdo emocional. Os sintomas acessĂłrios sĂŁo alucinaçÔes hipnagĂłgicas, paralisia do sono e sono fragmentado. CritĂ©rios de diagnĂłstico clĂnico de acordo com a Classificação Internacional dos Transtornos do Sono sĂŁo de sonolĂȘncia excessiva e cataplexia. Recomenda-se a realização de polissonografia seguida do teste de latĂȘncia mĂșltipla do sono em um laboratĂłrio de sono para confirmação e diagnĂłstico de comorbidades. Quando nĂŁo houver cataplexia, deve haver duas ou mais sonecas com sono REM no teste de latĂȘncia mĂșltipla do sono. Tipagem HLA-DQB1*0602 positiva com nĂveis de hipocretina-1 abaixo de 110pg/mL devem estar presentes para o diagnĂłstico de narcolepsia sem cataplexia e sem sonecas com sono REM.This manuscript contains the conclusion of the consensus meeting on the diagnosis of narcolepsy based on the review of Medline publications between 1980-2010. Narcolepsy is a chronic disorder with age at onset between the first and second decade of life. Essential narcolepsy symptoms are cataplexy and excessive sleepiness. Cataplexy is defined as sudden, recurrent and reversible attacks of muscle weakness triggered by emotions. Accessory narcolepsy symptoms are hypnagogic hallucinations, sleep paralysis and nocturnal fragmented sleep. The clinical diagnosis according to the International Classification of Sleep Disorders is the presence of excessive sleepiness and cataplexy. A full in-lab polysomnography followed by a multiple sleep latency test is recommended for the confirmation of the diagnosis and co-morbidities. The presence of two sleep-onset REM period naps in the multiple sleep latency test is diagnostic for cataplexy-free narcolepsy. A positive HLA-DQB1*0602 with lower than 110pg/mL level of hypocretin-1 in the cerebrospinal fluid is required for the final diagnosis of cataplexy- and sleep-onset REM period -free narcolepsy
Measurement of the cosmic ray spectrum above eV using inclined events detected with the Pierre Auger Observatory
A measurement of the cosmic-ray spectrum for energies exceeding
eV is presented, which is based on the analysis of showers
with zenith angles greater than detected with the Pierre Auger
Observatory between 1 January 2004 and 31 December 2013. The measured spectrum
confirms a flux suppression at the highest energies. Above
eV, the "ankle", the flux can be described by a power law with
index followed by
a smooth suppression region. For the energy () at which the
spectral flux has fallen to one-half of its extrapolated value in the absence
of suppression, we find
eV.Comment: Replaced with published version. Added journal reference and DO
Energy Estimation of Cosmic Rays with the Engineering Radio Array of the Pierre Auger Observatory
The Auger Engineering Radio Array (AERA) is part of the Pierre Auger
Observatory and is used to detect the radio emission of cosmic-ray air showers.
These observations are compared to the data of the surface detector stations of
the Observatory, which provide well-calibrated information on the cosmic-ray
energies and arrival directions. The response of the radio stations in the 30
to 80 MHz regime has been thoroughly calibrated to enable the reconstruction of
the incoming electric field. For the latter, the energy deposit per area is
determined from the radio pulses at each observer position and is interpolated
using a two-dimensional function that takes into account signal asymmetries due
to interference between the geomagnetic and charge-excess emission components.
The spatial integral over the signal distribution gives a direct measurement of
the energy transferred from the primary cosmic ray into radio emission in the
AERA frequency range. We measure 15.8 MeV of radiation energy for a 1 EeV air
shower arriving perpendicularly to the geomagnetic field. This radiation energy
-- corrected for geometrical effects -- is used as a cosmic-ray energy
estimator. Performing an absolute energy calibration against the
surface-detector information, we observe that this radio-energy estimator
scales quadratically with the cosmic-ray energy as expected for coherent
emission. We find an energy resolution of the radio reconstruction of 22% for
the data set and 17% for a high-quality subset containing only events with at
least five radio stations with signal.Comment: Replaced with published version. Added journal reference and DO
Measurement of the Radiation Energy in the Radio Signal of Extensive Air Showers as a Universal Estimator of Cosmic-Ray Energy
We measure the energy emitted by extensive air showers in the form of radio
emission in the frequency range from 30 to 80 MHz. Exploiting the accurate
energy scale of the Pierre Auger Observatory, we obtain a radiation energy of
15.8 \pm 0.7 (stat) \pm 6.7 (sys) MeV for cosmic rays with an energy of 1 EeV
arriving perpendicularly to a geomagnetic field of 0.24 G, scaling
quadratically with the cosmic-ray energy. A comparison with predictions from
state-of-the-art first-principle calculations shows agreement with our
measurement. The radiation energy provides direct access to the calorimetric
energy in the electromagnetic cascade of extensive air showers. Comparison with
our result thus allows the direct calibration of any cosmic-ray radio detector
against the well-established energy scale of the Pierre Auger Observatory.Comment: Replaced with published version. Added journal reference and DOI.
Supplemental material in the ancillary file
Estrutura de espécies arbóreas sob efeito de borda em um fragmento de floresta estacional semidecidual em Pernambuco
Brazilian guidelines for the diagnosis of narcolepsy
Este artigo relata as conclusĂ”es da reuniĂŁo de consenso com mĂ©dicos especialistas sobre diagnĂłstico de narcolepsia baseada na revisĂŁo dos artigos sobre narcolepsia listados no Medline entre 1980 e 2010. A narcolepsia Ă© uma doença crĂŽnica de inĂcio entre a primeira e segunda dĂ©cadas de vida do indivĂduo. Os sintomas essenciais sĂŁo cataplexia e sonolĂȘncia excessiva. A cataplexia Ă© definida como episĂłdios sĂșbitos, recorrentes e reversĂveis de fraqueza da musculatura esquelĂ©tica desencadeados por situaçÔes de conteĂșdo emocional. Os sintomas acessĂłrios sĂŁo alucinaçÔes hipnagĂłgicas, paralisia do sono e sono fragmentado. CritĂ©rios de diagnĂłstico clĂnico de acordo com a Classificação Internacional dos Transtornos do Sono sĂŁo de sonolĂȘncia excessiva e cataplexia. Recomenda-se a realização de polissonografia seguida do teste de latĂȘncia mĂșltipla do sono em um laboratĂłrio de sono para confirmação e diagnĂłstico de comorbidades. Quando nĂŁo houver cataplexia, deve haver duas ou mais sonecas com sono REM no teste de latĂȘncia mĂșltipla do sono. Tipagem HLA-DQB1*0602 positiva com nĂveis de hipocretina-1 abaixo de 110pg/mL devem estar presentes para o diagnĂłstico de narcolepsia sem cataplexia e sem sonecas com sono REM.This manuscript contains the conclusion of the consensus meeting on the diagnosis of narcolepsy based on the review of Medline publications between 1980-2010. Narcolepsy is a chronic disorder with age at onset between the first and second decade of life. Essential narcolepsy symptoms are cataplexy and excessive sleepiness. Cataplexy is defined as sudden, recurrent and reversible attacks of muscle weakness triggered by emotions. Accessory narcolepsy symptoms are hypnagogic hallucinations, sleep paralysis and nocturnal fragmented sleep. The clinical diagnosis according to the International Classification of Sleep Disorders is the presence of excessive sleepiness and cataplexy. A full in-lab polysomnography followed by a multiple sleep latency test is recommended for the confirmation of the diagnosis and co-morbidities. The presence of two sleep-onset REM period naps in the multiple sleep latency test is diagnostic for cataplexy-free narcolepsy. A positive HLA-DQB1*0602 with lower than 110pg/mL level of hypocretin-1 in the cerebrospinal fluid is required for the final diagnosis of cataplexy- and sleep-onset REM period -free narcolepsy.32329430
Brazilian guidelines for the diagnosis of narcolepsy
Este artigo relata as conclusĂ”es da reuniĂŁo de consenso com mĂ©dicos especialistas sobre diagnĂłstico de narcolepsia baseada na revisĂŁo dos artigos sobre narcolepsia listados no Medline entre 1980 e 2010. A narcolepsia Ă© uma doença crĂŽnica de inĂcio entre a primeira e segunda dĂ©cadas de vida do indivĂduo. Os sintomas essenciais sĂŁo cataplexia e sonolĂȘncia excessiva. A cataplexia Ă© definida como episĂłdios sĂșbitos, recorrentes e reversĂveis de fraqueza da musculatura esquelĂ©tica desencadeados por situaçÔes de conteĂșdo emocional. Os sintomas acessĂłrios sĂŁo alucinaçÔes hipnagĂłgicas, paralisia do sono e sono fragmentado. CritĂ©rios de diagnĂłstico clĂnico de acordo com a Classificação Internacional dos Transtornos do Sono sĂŁo de sonolĂȘncia excessiva e cataplexia. Recomenda-se a realização de polissonografia seguida do teste de latĂȘncia mĂșltipla do sono em um laboratĂłrio de sono para confirmação e diagnĂłstico de comorbidades. Quando nĂŁo houver cataplexia, deve haver duas ou mais sonecas com sono REM no teste de latĂȘncia mĂșltipla do sono. Tipagem HLA-DQB1*0602 positiva com nĂveis de hipocretina-1 abaixo de 110pg/mL devem estar presentes para o diagnĂłstico de narcolepsia sem cataplexia e sem sonecas com sono REM323294304CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTĂFICO E TECNOLĂGICO - CNPQSem informaçãoThis manuscript contains the conclusion of the consensus meeting on the diagnosis of narcolepsy based on the review of Medline publications between 1980-2010. Narcolepsy is a chronic disorder with age at onset between the first and second decade of life. Essential narcolepsy symptoms are cataplexy and excessive sleepiness. Cataplexy is defined as sudden, recurrent and reversible attacks of muscle weakness triggered by emotions. Accessory narcolepsy symptoms are hypnagogic hallucinations, sleep paralysis and nocturnal fragmented sleep. The clinical diagnosis according to the International Classification of Sleep Disorders is the presence of excessive sleepiness and cataplexy. A full in-lab polysomnography followed by a multiple sleep latency test is recommended for the confirmation of the diagnosis and co-morbidities. The presence of two sleep-onset REM period naps in the multiple sleep latency test is diagnostic for cataplexy-free narcolepsy. A positive HLA-DQB1*0602 with lower than 110pg/mL level of hypocretin-1 in the cerebrospinal fluid is required for the final diagnosis of cataplexy- and sleep-onset REM period -free narcoleps
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